FIELD OF THE INVENTION
The invention relates to an offset printing press wherein, as seen in the direction of rotation of a plate cylinder, a first applicator roller is assigned to a dampening unit and a second applicator roller to an inking unit, a bridge roller is in contact with the first and second applicator rollers, and a roller is in contact with the first applicator roller for driving the first applicator roller at the circumferential speed of the plate cylinder or at a different speed.
In a conventional embodiment of this printing press generally known from U.S. Pat. No. 4,724,764, the first applicator roller, as seen in the direction of rotation of the plate cylinder, is driven at a different circumferential speed from the circumferential speed of the plate cylinder, the drive of the first applicator roller preferably effecting a lower circumferential speed. Dirt particles are thereby supposed to be removed from the printing plate due to the wiping effect which occurs. In this conventional construction, the bridge roller also is driven at a different circumferential speed from the circumferential speed of the plate cylinder, so that the second applicator roller, which rotates at the circumferential speed of the plate cylinder, may be braked by the bridge roller. This risk arises, in particular, in the vicinity of the cylinder gap, so that an inking fault may occur after the second applicator roller reengages the printing plate.